Chip package thermal interface materials with dielectric obstructions for body-biasing, methods of using same, and systems containing same

ABSTRACT

A chip package includes a thermal interface material disposed between a die backside and a heat sink. The thermal interface material includes a first metal particle that is covered by a dielectric film. The dielectric film is selected from an inorganic compound of the first metal or an inorganic compound coating of a second metal. The dielectric film diminishes overall heat transfer from the first metal particle in the thermal interface material by a small fraction of total possible heat transfer without the dielectric film. A method of operating the chip includes biasing the chip with the dielectric film in place.

TECHNICAL FIELD

Embodiments relate generally to a chip package fabrication. Moreparticularly, embodiments relate to heat-transfer and current-leakageissues in chip packages.

TECHNICAL BACKGROUND

Issues that affect packaged integrated circuit (IC) devices include heatmanagement, current leakage, and clock speed, among others. An IC diethat cannot adequately reject heat will be adversely affected in clockspeed. An IC die that has significant current leakage through thebackside will also be adversely affected in clock speed.

As die size and package size continue to be miniaturized, currentleakage may exceed the current demand to operate the IC die. The mobileIC die segment of packaged IC devices is a particularly vulnerable areaof technology as it is desired to improve battery life by decreasingelectrical current demand, particularly by reducing current leakagethrough the backside surface of the die.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to depict the manner in which the embodiments are obtained, amore particular description of embodiments briefly described above willbe rendered by reference to exemplary embodiments that are illustratedin the appended drawings. Understanding that these drawings depict onlytypical embodiments that are not necessarily drawn to scale and are nottherefore to be considered to be limiting of its scope, the embodimentswill be described and explained with additional specificity and detailthrough the use of the accompanying drawings in which:

FIG. 1 is a cross-section elevation of an apparatus that includes aplurality of dielectric-coated metal particles in a thermal interfacematerial according to an embodiment;

FIG. 2 is a detail section taken from the apparatus depicted in FIG. 1according to an embodiment;

FIG. 3 is detail section taken from the structure depicted in FIG. 2according to an embodiment;

FIG. 4 is a cross-section elevation of an apparatus that includes athermal interface material that contains a plurality ofdielectric-coated metal particles in an integrated heat spreader packageaccording to an embodiment;

FIG. 5 is a cross-section elevation of an apparatus during the reworkingof a flexible thermal interface material that contains a plurality ofdielectric-coated metal particles according to an embodiment;

FIG. 6 is a cross-section elevation of an apparatus during the reworkingof a rigid thermal interface material that contains plurality ofdielectric-coated metal particles according to an embodiment;

FIG. 7 is a flow chart that describes process flow embodiments; and

FIG. 8 is a cut-away elevation that depicts a computing system accordingto an embodiment.

DETAILED DESCRIPTION

Embodiments in this disclosure relate to an apparatus that includes aplurality of dielectric-coated metal particles for heat transfer betweenan IC die and a heat spreader. Embodiments relate to both inorganic andorganic matrices into which the plurality of dielectric-coated metalparticles can be dispersed. Embodiments also relate to reworkableflexible and rigid thermal interface materials that contain a pluralityof dielectric-coated metal particles. Embodiments also relate toprocesses of assembling into chip packages, thermal interface materialsthat contain a plurality of dielectric-coated metal particles.Embodiments also relate to systems that incorporate a plurality ofdielectric-coated metal particles into a thermal interface material.

The following description includes terms, such as upper, lower, first,second, etc. that are used for descriptive purposes only and are not tobe construed as limiting. The embodiments of an apparatus or articledescribed herein can be manufactured, used, or shipped in a number ofpositions and orientations. The terms “die” and “chip” generally referto the physical object that is the basic workpiece that is transformedby various process operations into the desired integrated circuitdevice. A die is usually singulated from a wafer, and wafers may be madeof semiconducting, non-semiconducting, or combinations of semiconductingand non-semiconducting materials. A board is typically aresin-impregnated fiberglass structure that acts as a mounting substratefor the die.

Reference will now be made to the drawings wherein like structures willbe provided with like suffix reference designations. In order to showthe structures of various embodiments most clearly, the drawingsincluded herein are diagrammatic representations of integrated circuitstructures. Thus, the actual appearance of the fabricated structures,for example in a photomicrograph, may appear different while stillincorporating the essential structures of the illustrated embodiments.Moreover, the drawings show the structures necessary to understand theillustrated embodiments. Additional structures known in the art have notbeen included to maintain the clarity of the drawings.

FIG. 1 is a cross-section elevation of an apparatus 100 that includes aplurality of dielectric-coated metal particles in a thermal interfacematerial according to an embodiment. The apparatus 100 includes a die110 with an active surface 112 and a backside surface 114. The die 110can be electrically bumped by a plurality of solder bumps, one of whichis designated with the reference numeral 116. The die 110 is disposedupon a mounting substrate 118 that can be a board such as a printedwiring board, an interposer, a mezzanine board, an expansion card, amotherboard, or other mounting substrates. Electrical communicationbetween the die 110 and the outside world can be achieved by a pluralityof mounting substrate bumps, one of which is designated with thereference numeral 120 according to an embodiment.

The die 110 is thermally coupled to a thermal interface material (TIM)122 that is a significant conductor of heat. In an embodiment, the die110 includes a backside metallurgy 124 (BSM) that can be applied duringthe wafer phase of processing. The BSM 124 can assist the TIM 122 inadhering to the die 110. For example in FIG. 1, the die 110 and the TIM122 are depicted as including the BSM 124 bonded to the die 110 and tothe TIM 122 as a unit. The die 110, the BSM 124, and the TIM 122 arethermally coupled to a heat sink 126. Accordingly, electricallyconductive paths between the die 110 and the heat sink 126 areobstructed by the plurality of dielectric-coated metal particles 122.

The thermal solution for conductively cooling the die 110 includesextracting heat through the backside surface 114 of the die 110 and intothe heat sink 126. In an embodiment, the TIM 122 includes a plurality ofmetal particles such as copper, aluminum, silver, tin, tin-silver,tin-indium-silver, and the like, which metal particles are coated with adielectric film. In an embodiment, the TIM 122 is a dielectric-coatedmetal and polymer hybrid, which is often referred to as a polymer-solderhybrid (PSH). In an embodiment, the TIM 122 is a dielectric-coated metaland resin hybrid, which can have a rigidity greater than a PSH. In anembodiment, the TIM 122 is a dielectric-coated metal and thermal greasehybrid, which allows for significant thermal expansion and contractionof the TIM 122. In an embodiment, the TIM 122 is a dielectric-coatedmetal and silicone compound hybrid. In an embodiment, the TIM 122 is adielectric-coated metal and epoxy hybrid. In an embodiment, the TIM 122is a dielectric-coated metal and phase-change material hybrid.Accordingly, the phase-change material can be designed to change phasein a temperature range between room temperature and the heat-rejectiontemperature of the IC die that is packaged with the TIM.

In an embodiment, the BSM 124 is a titanium compound such as sputteredtitanium metal. In an embodiment, the BSM 124 includes a titanium firstlayer disposed against the bare die 110 at the backside surface 114, anda multiphasic, lead-free solder second layer disposed on the firstlayer. In an embodiment, the lead-free solder second layer is a materialwith a bulk solder phase such as AgSn, CuSn, AgCu, AgCuSn, and the like.

In addition to the lead-free solder bulk phase, the lead-free soldersecond layer includes an intermetallic second phase that liquefies anddissolves into the first phase during die-attach processing. Theintermetallic second phase includes an InBiZn as an additive to thefirst phase. The intermetallic second phase causes enhanced wetting uponthe titanium first layer at a temperature range from about 95° C. toabout 110° C. In this embodiment, the lead-free solder second layer isan AgSn solder first phase that includes about 80% to about 95% of thesolder, and the intermetallic-forming second phase is a zinc-gold-indiumintermetallic compound that includes the balance of the solder byweight, about 5% to about 20%. In this embodiment, the zinc-gold-indiumintermetallic compound is present with about three parts zinc, fiveparts Au, and about one part indium.

FIG. 2 is a detail section taken from the apparatus 100 depicted in FIG.1 according to an embodiment. The detail section is taken along the line2, which includes the TIM 122 and the heat sink 126. The detail sectionalso reveals the plurality of metal particles, one of which isdesignated with the reference numeral 128. In an embodiment, eachparticle of the plurality of metal particles 128 includes a metal core130 and a dielectric film 132 upon the metal core 130. In an embodiment,a majority of the first metal particles 128 includes a metal core 130and a dielectric film 132, but a minority of the first metal particles128 includes a metal core and a less than complete dielectric film 132.In an embodiment, a majority of the first metal particles 128 includes ametal core 130 and a dielectric film 132, but in the majority of thefirst metal particles 128 with a dielectric film 132, a plurality of thefirst metal particles 128 includes a metal core and a completedielectric film 132. In other words by way of example, a plurality offirst metal particles 128, e.g., 40 percent thereof are completelyencapsulated by a dielectric film 132, 30 percent of the metal particlesare less than completely encapsulated by a dielectric film 132, and 30percent of the metal particles 128 have no dielectric film.

The combination of the metal core 130 and the dielectric film 132thereupon in the TIM 122 results in a decreased heat-transfercapability, compared to a TIM 122 containing all metal particles 128without a dielectric film 132. In other words, if all of the metalparticles 130 had no dielectric film 132, the TIM 122 could perform witha heat-transfer capability of unity, i.e., in dimensionless units suchas in Watts/m². But in this disclosure, the TIM 122 includes the metalcore 130 and the dielectric film 132, and consequently the dielectricfilm 132 decreases the heat-transfer capability of the TIM 122 by notmore than about 20 percent of unity according to an embodiment. In anembodiment, the dielectric film 132 decreases the heat-transfercapability of the TIM 122 compared to the metal particles alone, by notmore than about 10 percent of unity. In an embodiment, the dielectricfilm 132 decreases the heat-transfer capability of the TIM 122 comparedto metal particles alone, by not more than about one percent of unity.In an embodiment, the dielectric film 132 decreases the heat-transfercapability of the TIM 122 compared to metal particles alone, by not morethan about 0.5 percent of unity.

FIG. 3 is detail section taken from the structure depicted in FIG. 2according to an embodiment. The detail section is taken along the line3, which includes the metal core 130 and the dielectric film 132thereupon. The detail section also reveals a matrix 134 in which theplurality of first metal particles 128 is dispersed according to anembodiment. In an embodiment, the metal core 130 has an average-diameterparticle size range from about 20 nanometers to about 25 micrometers. Inan embodiment, the metal core 130 has an average-diameter particle sizerange from about 20 nanometers to about 1,000 nanometers and thedielectric film 132 on particles of this size range has a thickness,relative to the average-diameter particle size in a range from about 0.1percent to about 1 percent. In an embodiment, the metal core 130 has anaverage-diameter particle size range from about 0.1 micrometers to about25 micrometers and the dielectric film 132 on particles of this sizerange has a thickness, relative to the average-diameter particle size ina range from about 1 percent to about 5 percent.

In an embodiment, the TIM 122 has a thickness of about 1,000 micrometers(μm). In an embodiment, the TIM 122 has a thickness of about 500 μm. Inan embodiment, the TIM 122 has a thickness of about 100 μm. In anembodiment, the TIM 122 has a thickness of about 50 μm. In anembodiment, the TIM 122 has a thickness of about 10 μm. In anembodiment, the TIM 122 has a thickness that is about twice thethickness of the average-diameter particle size of the metal core 130.Accordingly the TIM 122 can have a thickness that is greater than thediameter smallest metal core 130 by about double. In an embodiment, theTIM 122 has a thickness that is about 10 times the average-diameterparticle size of the metal core 130. In an embodiment, the TIM 122 has athickness that is about 100 times the thickness of the average-diameterparticle size of the metal core 130. In an embodiment, the TIM 122 has athickness that is about 500 times the thickness of the average-diameterparticle size of the metal core 130. In an embodiment, the TIM 122 has athickness that is about 1,000 times the thickness of theaverage-diameter particle size of the metal core 130.

Preparation of the TIM 122, including the dielectric-coated particles122 can be done, for example, by kneading the dielectric-coatedparticles 122 with a polymer matrix material 134, such that asubstantially uniformly blended composite is achieved. Accordingly in anembodiment, the dielectric film 132 is entirely surrounded by the matrix134 such that an additional layer of dielectric material, the matrix134, obstructs eclectically conductive paths between the die 110 and theheat sink 126. Where the TIM 122 includes a first metal of the core 130,the dielectric film 132 of any disclosed type, and the matrix 134includes a second metal as disclosed, preparation of the TIM 122 caninclude blending of the plurality of first metal particles 128 with apowder of second metal particles, followed by sintering or heating toachieve the liquidus temperature of the second metal, and by optionalpressing during sintering or liquidus heating.

Metal Cores and Dielectric Films

The metal core 130 can be processed according to various embodiments toobtain the dielectric film 132. In an embodiment, the dielectric film132 is a corrosion result of the metal core 130. For example, where themetal core is copper, the dielectric film 132 is copper oxide accordingto an embodiment. In an embodiment, the dielectric film 132 is a nitrideof the metal core 130. In an embodiment, the dielectric film 132 is anoxynitride of the metal core 130. In an embodiment, the dielectric film132 is a carbide of the metal core 130. In an embodiment, the dielectricfilm 132 is a sulfide of the metal core 130. In an embodiment, thedielectric film 132 is a boride of the metal core 130. In an embodiment,the dielectric film 132 is a boronitride of the metal core 130. Otherqualitative corrosion results of the metal core 130 can be used.Additionally, any disclosed quantitative thickness for the dielectricfilm 132 as a percentage of the average diameter of any disclosed metalcore 130, can be combined with any disclosed TIM 122 thickness toachieve several embodiments. For example, a metal core 130 of copper hasan average particle diameter of about 20 μm and a Cu₂O dielectric film132 that is about three percent of the 20 μm average particle diameter.

Preparation of the dielectric film 132 to achieve a corrosion result canbe done, for example, by heating the metallic particles in an oxidatingenvironment. In an embodiment, the metal core 130 is treated in afluidized bed of corrosive gas. For example, a plurality of copperparticles 130 is fluidized in an oxygen-sparging environment until thecopper particles have a copper metal core 130 and have grown a copperoxide dielectric film 132. Similarly, a plurality of copper particles isfluidized in an ammonia and nitrogen-sparging environment until thecopper particles have a copper metal core 130 and a have grown a coppernitride dielectric film 132.

In an embodiment, the dielectric film 132 is an applied coating on themetal core 130. For example, where the metal core is copper, thedielectric film 132 includes boron nitride, which is formed upon thecopper by a process such as chemical vapor deposition (CVD).Accordingly, the metal core 130 includes a first metal or a first metalalloy, and the dielectric film 132 includes a compound that is derivedfrom a second metal or second metal alloy. In an embodiment, the firstmetal or first metal alloy of the metal core 130 is combined with adielectric film 132 that is an oxide of the second metal that is unlikethe first metal or metal alloy. By “unlike the first metal or metalalloy”, it is meant that an analytical chemist of ordinary skill coulddetermine by conventional analysis that the first metal and the secondmetal have detectably qualitatively different properties. In anembodiment, the first metal or first metal alloy of the metal core 130is combined with a dielectric film 132 that is a metal-nitride of thesecond metal that is unlike the first metal. In an embodiment, the firstmetal or first metal alloy of the metal core 130 is combined with adielectric film 132 that is an oxynitride of the second metal. In anembodiment, the first metal or first metal alloy of the metal core 130is combined with a dielectric film 132 that is carbide of the secondmetal. In an embodiment, the first metal or first metal alloy of themetal core 130 is combined with a dielectric film 132 that is a sulfideof the second metal. In an embodiment, the first metal or first metalalloy of the metal core 130 is combined with a dielectric film 132 thatis a boride of the second metal. In an embodiment, the first metal orfirst metal alloy of the metal core 130 is combined with a dielectricfilm 132 that is a boronitride of the second metal.

Preparation of the dielectric film 132 to achieve an applied-coatingresult can be done, for example, by PVD of a mechanically agitated bedof metallic particles in a PVD tool. In an embodiment, a PVD toolincludes a vibrating device, which vibrates a boat that contains a thinlayer of copper particles. Vibration of the boat keeps the metallicparticles fluidized during which time PVD of, e.g., BN is carried out onthe copper particles until the copper particles have a copper metal core130 and a have grown a BN dielectric film 132.

TIM Matrix Materials

Where the TIM 122 includes a matrix 134, the matrix has the quality ofadhesion to the heat sink 136 and to the die 110 or to the BSM 124 ifpresent. In an embodiment, the matrix 134 is a polymer. In anembodiment, the matrix 134 is a resin. In an embodiment, the matrix 134is a thermal grease. In an embodiment, the matrix 134 is a siliconecompound. In an embodiment, the matrix 134 is an epoxy. In anembodiment, the matrix is 134 a phase-change material. In an embodiment,the matrix 134 is a second metal compared to the first metal of themetal core 130. In an embodiment, however, the second metal can besubstantially chemically the same metal as the first metal of the metalcore 130, but the metal core 130 includes a dielectric film 132, whetherit is a corrosion product or an adhesion product as set forth in thisdisclosure.

FIG. 4 is a cross-section elevation of an apparatus 400 that includes athermal interface material that contains a plurality ofdielectric-coated metal particles in an integrated heat spreader packageaccording to an embodiment. The apparatus 400 includes a die 410 with anactive surface 412 and a backside surface 414. The die 410 can beelectrically bumped by a plurality of solder bumps, one of which isdesignated with the reference numeral 416. The die 410 is disposed upona mounting substrate 418 that can be a board such as a printed wiringboard, an interposer, a mezzanine board, an expansion card, amotherboard, or other mounting substrates. Electrical communicationbetween the die 410 and the outside world can be achieved by a pluralityof mounting substrate bumps, one of which is designated with thereference numeral 420 according to an embodiment.

The die 410 is thermally coupled to a TIM 422 that is a significantconductor of heat. In an embodiment, the die 410 includes a BSM 424 thatcan be applied during the wafer phase of processing. The BSM 424 canassist the TIM 422 in adhering to the die 410. For example in FIG. 4,the die 410 and the TIM 422 are depicted as including the BSM 424 bondedto the die 410 and to the TIM 422 as a unit. The die 410, the BSM 424,and the TIM 422 are thermally coupled to a heat sink 426. Accordingly,electrically conductive paths between the die 410 and the integratedheat spreader 426 are obstructed by the dielectric-coating (e.g. 132,FIG. 3) on the metal particles 130. Similarly, where the matrix 134 isalso dielectric, electrically conductive paths between the die 410 andthe integrated heat spreader 426 are obstructed by the matrix 134.

The thermal solution for conductively cooling the die 410 includesextracting heat through the backside surface 414 of the die 410 and intothe integrated heat spreader 426.

The combination of the metal core and the dielectric film thereupon inthe TIM 422 results in a decreased heat-transfer capability; compared toif the TIM 422 contained the metal particles without a dielectric film.In other words, if the metal particles had no dielectric film, the TIM422 could perform with a heat-transfer capability of unity, i.e., indimensionless units such as in Watts/m². But in this disclosure, the TIM422 includes the metal core and the dielectric film, and consequentlythe dielectric film decreases the heat-transfer capability of the TIM422 by not more than about 20 percent of unity according to anembodiment. In an embodiment, the dielectric film decreases theheat-transfer capability of the TIM 422 compared to the metal particlesalone, by not more than about 10 percent of unity. In an embodiment, thedielectric film decreases the heat-transfer capability of the TIM 422compared to metal particles alone, by not more than about one percent ofunity. In an embodiment, the dielectric film decreases the heat-transfercapability of the TIM 422 compared to metal particles alone, by not morethan about 0.5 percent of unity.

FIG. 5 is a cross-section elevation of an apparatus during the reworkingof a flexible thermal interface material that contains a plurality ofdielectric-coated metal particles according to an embodiment. Theapparatus 500 includes a die 510 with an active surface 512 and abackside surface 514. The die 510 can be electrically bumped by aplurality of solder bumps, one of which is designated with the referencenumeral 516. The die 510 is disposed upon a mounting substrate 518 thatcan be a board such as a printed wiring board, an interposer, amezzanine board, an expansion card, a motherboard, or other mountingsubstrates. Electrical communication between the die 510 and the outsideworld can be achieved by a plurality of mounting substrate bumps, one ofwhich is designated with the reference numeral 520 according to aembodiment.

In an embodiment, reworking of the thermal solution for the die 510includes removing a TIM 522 and installing a replacement TIM. Asdepicted in FIG. 5, the TIM 522 is disposed directly upon a BSM 524 ofthe die 510. Where the TIM 522 is flexible, it can be peeled off the BSM524 if present, or it can be peeled off the backside surface 514 of thedie 510 if the BSM 524 is not present. The TIM 522 is being peeled offin the direction of the directional arrow 536.

Reworking the thermal solution according to these embodiments can beachieved during initial processing before shipping, if a different TIMis desired to replace the TIM 522. Similarly, reworking the thermalsolution according to these embodiments can be achieved after shipping,i.e., if the apparatus 500 requires a different thermal solution thanthat with it was shipped.

FIG. 6 is a cross-section elevation of an apparatus 600 during thereworking of a rigid thermal interface material that contains pluralityof dielectric-coated metal particles according to an embodiment. Theapparatus 600 includes a die 610 with an active surface 612 and abackside surface 614. The die 610 can be electrically bumped by aplurality of solder bumps, one of which is designated with the referencenumeral 616. The die 610 is disposed upon a mounting substrate 618 thatcan be a board such as a printed wiring board, an interposer, amezzanine board, an expansion card, a motherboard, or other mountingsubstrates. Electrical communication between the die 610 and the outsideworld can be achieved by a plurality of mounting substrate bumps, one ofwhich is designated with the reference numeral 620 according to aembodiment.

In an embodiment, reworking of the thermal solution for the die 610includes removing a TIM 622 and installing a replacement TIM. Asdepicted in FIG. 6, the TIM 622 is disposed directly upon a BSM 624 ofthe die 610. Where the TIM 622 is rigid such as an oxide, a nitride, ametal matrix, or others, it can be removed from the BSM 624 by grindingif present, or it can be ground off the backside surface 614 of the die610 if the BSM 624 is not present. The TIM 622 is being ground off inthe direction of the directional arrow 638, with a grinding wheel 640according to an embodiment.

Reworking the thermal solution according to these embodiments can beachieved during initial processing if a different TIM is desired toreplace the TIM 622. Similarly, reworking the thermal solution accordingto these embodiments can be achieved after shipping, i.e., if theapparatus 600 requires a different thermal solution than that with itwas shipped.

In an embodiment, a method of operating an IC device includes applying abias to a die. Reference is made to FIG. 1. In an embodiment, a biasthat is a fraction of the voltage requirement of the die 110 is appliedacross the solder bumps 116, such that a field effect is imposed uponthe entire integrated circuitry of the die 110. Accordingly, currentleakage diminishes. In an embodiment, a bias in a range from about fivepercent to about 50 percent of the voltage requirement of the die 110 isapplied across the solder bumps 116, such that a field effect is imposedupon the entire integrated circuitry of the die 110. Accordingly,current leakage diminishes. In an embodiment, the voltage that isapplied is a range from about 1 Volt to about 6 Volts. In an embodiment,a bias of about five percent of the voltage requirement of the die 110,about 3.5 Volts, is applied across the solder bumps 116, such that afield effect is imposed upon the entire integrated circuitry of the die110. Accordingly, current leakage diminishes.

In an embodiment, the IC device that includes a TIM that contains aplurality of dielectric-coated metal particles embodiment is a mobiledevice such as the apparatus 100 depicted in FIG. 1. In an embodiment,the IC device is a desktop device such as the apparatus 400 depicted inFIG. 4.

FIG. 7 is a flow chart that describes process flow embodiments 700.

At 710, the process includes forming a TIM that includes a plurality ofdielectric-coated metallic particles. In an embodiment, the processincludes forming a dielectric coating on the metal core, whether as acorrosion product or as an applied film. In an embodiment, the processcommences and terminates at 710. At 712, the process includes removingthe TIM and installing a replacement TIM.

At 720, the process includes coupling the TIM embodiment between an ICdie and a heat sink to form an IC chip package. In an embodiment, theprocess commences at 710 and terminates at 720. In an embodiment, theprocess commences and terminates at 720. At 712, the process includesremoving the TIM and installing a replacement TIM, followed by couplingthe TIM embodiment between an IC die and a heat sink to form an IC chippackage at 720.

At 730, the process includes installing the IC chip package into astructure to form a computing system. In an embodiment, the processcommences at 730 and terminates at 730. In an embodiment, the processcommences at 710 and terminates at 740. In an embodiment, the processcommences at 720 and terminates at 740. At 712, the process includesremoving the TIM and installing a replacement TIM, followed byinstalling the IC chip package into a structure to form a computingsystem at 730.

FIG. 8 is a cut-away elevation that depicts a computing system 800according to an embodiment. One or more of the foregoing embodiments ofthe TIM-containing plurality of dielectric-coated metal particles may beutilized in a computing system, such as a computing system 800 of FIG.8. Hereinafter any TIM-containing plurality of dielectric-coated metalparticles embodiment alone or in combination with any other embodimentis referred to as an embodiment(s) configuration.

The computing system 800 includes at least one processor (not pictured),which is enclosed in an IC chip package 810, a data storage system 812,at least one input device such as a keyboard 814, and at least oneoutput device such as a monitor 816, for example. The computing system800 includes a processor that processes data signals, and may include,for example, a microprocessor, available from Intel Corporation. Inaddition to the keyboard 814, the computing system 800 can includeanother user input device such as a mouse 818, for example. Thecomputing system 800 can include a structure, after processing asdepicted in FIGS. 1, 2, and 3, including the die 110, the plurality ofdielectric-coated metal particles 128, optionally the matrix 134, andthe heat spreader 126.

For purposes of this disclosure, a computing system 800 embodyingcomponents in accordance with the claimed subject matter may include anysystem that utilizes a microelectronic device system, which may include,for example, at least one of the TIM-containing plurality ofdielectric-coated metal particles embodiments that is coupled to datastorage such as dynamic random access memory (DRAM), polymer memory,flash memory, and phase-change memory. In this embodiment, theembodiment(s) is coupled to any combination of these functionalities bybeing coupled to a processor. In an embodiment, however, anembodiment(s) configuration set forth in this disclosure is coupled toany of these functionalities. For an example embodiment, data storageincludes an embedded DRAM cache on a die. Additionally in an embodiment,the embodiment(s) configuration that is coupled to the processor (notpictured) is part of the system with an embodiment(s) configuration thatis coupled to the data storage of the DRAM cache. Additionally in anembodiment, an embodiment(s) configuration is coupled to the datastorage 812.

In an embodiment, the computing system 800 can also include a die thatcontains a digital signal processor (DSP), a micro controller, anapplication specific integrated circuit (ASIC), or a microprocessor. Inthis embodiment, the embodiment(s) configuration is coupled to anycombination of these functionalities by being coupled to a processor.For an example embodiment, a DSP is part of a chipset that may include astand-alone processor and the DSP as separate parts of the chipset onthe board 820. In this embodiment, an embodiment(s) configuration iscoupled to the DSP, and a separate embodiment(s) configuration may bepresent that is coupled to the processor in the IC chip package 810.Additionally in an embodiment, an embodiment(s) configuration is coupledto a DSP that is mounted on the same board 820 as the IC chip package810. It can now be appreciated that the embodiment(s) configuration canbe combined as set forth with respect to the computing system 800, incombination with an embodiment(s) configuration as set forth by thevarious embodiments of the TIM-containing plurality of dielectric-coatedmetal particles within this disclosure and their equivalents.

It can now be appreciated that embodiments set forth in this disclosurecan be applied to devices and apparatuses other than a traditionalcomputer. For example, a die can be packaged with an embodiment(s)configuration, and placed in a portable device such as a wirelesscommunicator or a hand-held device such as a personal data assistant andthe like. Another example is a die that can be packaged with anembodiment(s) configuration and placed in a vehicle such as anautomobile, a locomotive, a watercraft, an aircraft, or a spacecraft.

The Abstract is provided to comply with 37 C.F.R. §1.72(b) requiring anabstract that will allow the reader to quickly ascertain the nature andgist of the technical disclosure. It is submitted with the understandingthat it will not be used to interpret or limit the scope or meaning ofthe claims.

In the foregoing Detailed Description, various features are groupedtogether in a single embodiment for the purpose of streamlining thedisclosure. This method of disclosure is not to be interpreted asreflecting an intention that the claimed embodiments of the inventionrequire more features than are expressly recited in each claim. Rather,as the following claims reflect, inventive subject matter lies in lessthan all features of a single disclosed embodiment. Thus the followingclaims are hereby incorporated into the Detailed Description, with eachclaim standing on its own as a separate preferred embodiment.

It will be readily understood to those skilled in the art that variousother changes in the details, material, and arrangements of the partsand method stages which have been described and illustrated in order toexplain the nature of this invention may be made without departing fromthe principles and scope of the invention as expressed in the subjoinedclaims.

1. An apparatus comprising: a die including an active surface and abackside surface; a heat sink disposed above the die; and a thermalinterface material disposed between the die backside surface and theheat sink, wherein the thermal interface material includes a pluralityof first metal particles, wherein at least some of the first metalparticles include a dielectric film disposed thereon, and whereinelectrically conductive paths between the die and the heat sink areobstructed by the dielectric film.
 2. The apparatus of claim 1, whereina plurality of the first metal particles includes a complete dielectricfilm.
 3. The apparatus of claim 1, wherein a majority of the first metalparticles includes a complete dielectric film.
 4. The apparatus of claim1, wherein the dielectric film is selected from an oxide of the firstmetal, a nitride of the first metal, an oxyntride of the first metal, acarbide of the first metal, a sulfide of the first metal, a boride ofthe first metal, a boronitride of the first metal, and combinationsthereof.
 5. The apparatus of claim 1, wherein the dielectric filmincludes an a second metal compound that includes at least one of anoxide of the second metal, a nitride of the second metal, an oxynitrideof the second metal, a carbide of the second metal, a sulfide of thesecond metal, a boride of the second metal, a boronitride of the secondmetal, and combinations thereof, and wherein the first metal and thesecond metal are qualitatively different.
 6. The apparatus of claim 1,wherein the first metal is present in a particle size range from about20 nanometers to about 25 micrometers.
 7. The apparatus of claim 1,wherein the first metal is present in a particle size range from about20 nanometers to about 25 micrometers, and wherein the dielectric filmincludes a thickness relative to the particle size in a range from about0.1 percent to about 5 percent.
 8. The apparatus of claim 1, wherein thethermal interface material further includes a matrix in which theplurality of first metal-particles is dispersed.
 9. The apparatus ofclaim 1, wherein the thermal interface material further includes amatrix in which the plurality of first metal-particles is dispersed, andwherein the matrix is selected from a polymer, a resin, a thermalgrease, a silicone compound, an epoxy, a phase-change material, a metal,and combinations thereof.
 10. The apparatus of claim 1, wherein thethermal interface material further includes a matrix in which theplurality of first metal-particles is dispersed, wherein the matrix isselected from a polymer, a resin, a thermal grease, a silicone compound,an epoxy, a phase-change material, a metal, and combinations thereof,and wherein the matrix includes a volume of the thermal interfacematerial, relative to the plurality of first metal-particles in a rangefrom about 1 percent to about 70 percent.
 11. The apparatus of claim 1,wherein the heat sink is selected from a planar heat slug and anintegrated heat spreader.
 12. The apparatus of claim 1, wherein thefirst metal has a heat-transfer capability of unity, and wherein thedielectric film decreases the heat-transfer capability of the firstmetal to not less than 10 percent of unity.
 13. The apparatus of claim1, wherein the thermal interface material is reworkable.
 14. Theapparatus of claim 1, further including a backside metallurgy disposedon the backside surface.
 15. A process comprising: forming a thermalinterface material between the backside surface of a die and a heatsink, wherein the thermal interface material includes a plurality offirst metal particles, wherein at least a plurality of the first metalparticles includes a dielectric film disposed thereon, and whereinelectrically conductive paths between the die and the heat sink areobstructed by the dielectric film.
 16. The process of claim 15, furtherincluding removing the thermal interface material and forming areplacement thermal interface material between the die and the heatsink.
 17. The process of claim 15, wherein the at least plurality offirst metal particles achieves the dielectric film disposed thereon by aprocess selected from forming a native oxide film thereon, forming athermal oxide film thereon, depositing a dielectric coating thereon, andcombinations thereof.
 18. A method comprising: applying a bias to a diepackage, the die package including: an active surface and a backsidesurface of the die; a heat sink disposed above the die; and a thermalinterface material disposed between the die backside surface and theheat sink, wherein the thermal interface material includes a pluralityof first metal particles, wherein at least a plurality of the firstmetal particles includes a dielectric film disposed thereon, and whereinelectrically conductive paths between the die and the heat sink areobstructed by the dielectric film.
 19. The method of claim 18, whereinapplying the bias includes applying the bias to the die enclosed in amobile device.
 20. The method of claim 18, wherein applying the biasincludes applying a bias in a range from about 0.1 Volt to about 6 Volt.21. A system comprising: a die including an active surface and abackside surface; a heat sink disposed above the die; and a thermalinterface material disposed between the die backside surface and theheat sink, wherein the thermal interface material includes a pluralityof first metal-particles, wherein at least a plurality of the firstmetal particles includes a dielectric film disposed thereon, and whereinelectrically conductive paths between the die and the heat sink areobstructed by the dielectric film; and dynamic random-access memorycoupled to the die.
 22. The system of claim 21, wherein the dielectricfilm is selected from an oxide of the first metal, a nitride of thefirst metal, an oxyntride of the first metal, a carbide of the firstmetal, a sulfide of the first metal, a boride of the first metal, aboronitride of the first metal, and combinations thereof.
 23. The systemof claim 21, wherein the system is disposed in one of a computer, awireless communicator, a hand-held device, an automobile, a locomotive,an aircraft, a watercraft, and a spacecraft.
 24. The system of claim 21,wherein the die is selected from a data storage device, a digital signalprocessor, a micro controller, an application specific integratedcircuit, and a microprocessor.